Vladimir Prelovac just posted some neat tips for plugin developers over on mashable. Here’s one that I really think needs more attention:

#8
WordPress plugins can sometimes be a real resource hog. To make sure your plugin isn’t, you need to localize the usage of resources, by loading them only when you need them.

You can use the following example to execute certain code (like declare additional actions and filters) only when WordPress is loading plugins.php page (list of installed plugins in the backend):

$local_pages=array(’plugins.php’); // define pages we want the plugin to be activated on

if (in_array($pagenow, $local_pages))
{
// do stuff here
}

Similar to this, you should pay attention to load JavaScript files only when you need them.

All too often I find plugins, like contact forms being loaded on every single page. It’s not that hard to figure out where the user likes to put their contact form, or whatever your plugin does. And while these tips were geared for plugin developers, theme authors should take this advice too as theming becomes more advance and not just an new stylesheet addition.

I’m looking forward to hearing more things like this on the next WP Weekly episode where Jeff interviews him.